Conventional loudspeakers that employ single drivers per frequency band (typically two-way, up to five-way) exhibit a directivity pattern, which varies with driver sizes, loudspeaker enclosure depth, baffle width and shape, and crossover filter design. The directivity pattern is, in general, strongly frequency-dependent and difficult to control. In particular, vertical lobing may occur because drivers are non-coincident with respect to the radiated wavelength, and directivity widens considerably towards mid- and low frequencies, thus emitting sound energy into all room directions, rather than to the listener, as intended. Normally, acoustic treatment is necessary to dampen unwanted reflections and to assure precise stereo imaging.